Bottom dump door actuating mechanism for vehicles



Dec. 5, 1967 R KRESS ET AL 3,356,416

BOTTOM DUMP DOOR ACTUATING MECHANISM FOR VEHTCLES Filed Oct. 23, 1965 3Sheets-$heet 1 INVENTORS RALPH H. KRESS JACKSON C. MEDLEY DONALD E.MERRITT ATTORNEYS Dec. 5, 1967 R H, KRESS ET AL 3,356,416

BOTTOM DUMP DOOR ACTUATING MECHANISM FOR VEHICLES 5 Sheets-Sheet 2 FiledOct. 23, 1965 INVENTORS RALPH H. KRESS JACKSON Q MEDLEY DONALD E.MEZRWTT ATTORNEYS Dec. 5, 196-7 KRESS ET AL BOTTOM DUMP DOOR ACTUATlNGMECHANISM FOR VEHICLES 5 Sheets-Sheet Filed Oct. 23, 1965 INVENTORSRALPH H. KRESS JACKSON c. MEDLEY DONALD E- MERRITT P g a. r4 .0

ATTORNEYS United States Patent 3,356,416 BOTTOM DUMP DOOR ACTUATINGMECHANISM FOR VEHICLES Ralph H. Kress, Peoria, Jackson C. Medley, EastPeoria, and Donald E. Merritt, Peoria Heights, Ill., assignors toCaterpillar Tractor Co., Peoria, Ill., a corporation of California FiledOct. 23, 1965, Ser. No. 503,037 1 Claim. (Cl. 298-35) ABSTRACT OF THEDISCLOSURE Pivoted bottom dump vehicle doors having linkage means withan extensible jack connected therewith; the jack body having meanscontained therein to effect either partial or full opening of thevehicle doors.

This invention relates to power actuated mechanism for Opening andclosing the doors on bottom dump trucks or the like.

The invention is designed particularly for very large material haulingvehicles such as the 240 ton capacity vehicle disclosed in our assigneesco-pending application of Ralph H. Kress and Jackson C. Medley entitledSuspension System for Heavy Vehicles, filed September 21, 1965, Serial.No. 488,985.

Vehicles of the kind disclosed herein are often used in miningoperations and their contents dumped through bottom opening doors intobins or the like where it is desired that the doors be only partiallyopened to avoid spilling the material on the sides of the bins and inthe path of travel of the vehicle wheels. It is also desirable sometimesto dump material in Windrows and in this case the doors should be fullyopen.

It is an object of the invention to provide actuating mechanism to openand close bottom dump doors in which the doors may be selectivelypartially or fully opened. It is a further object of the invention toprovide hydraulic actuating means for doors of the kind describedcomprising a hydraulic motor and means to prevent the weight of thedoors when they are closed and the weight of the load on the doors frombeing transmitted to the hydraulic motors.

It is a still further object of the present invention to provide aspecial hydraulic jack which is operable, selectively through a shortstroke or a long stroke for causing partial and full opening of doors orthe like.

Still further objects and advantages of the invention are made apparentin the following specification wherein reference is made to theaccompanying drawings for a detailed disclosure.

In the drawings:

FIG. 1 is a view in side elevation of a large truck embodying thepresent invention;

FIG. 2 is a sectional view with parts broken away and taken on the lineIIII of FIG. 1;

FIG. 3 is a central longitudinal section view through a hydraulic jackused for actuating the bottom dump doors to which the inventionpertains; and,

FIG. 4 is a perspective view illustrating structural details of thelinkage mechanism of the present invention.

The truck shown in FIG. 1 has a large body for carrying material whichmay be discharged from bottom dump doors to be described. Two largetractor units 12 and 14 support the body 10 through king pins 15 and 16.Each tractor unit has its own operators cab 17 and 18 equipped with dualcontrols so that all operations can be controlled from either cab. Apartition shown in dotted lines at 20 extends transversely of the truckbody midway between its ends for strengthening the body and to provideice a space for door actuating mechanism where it is protected fromdamage by contact with materials being hauled.

The arrangement of door actuating mechanism Within the space provided bythe partition 20 is shown in FIG. 2 wherein the near wall of thepartition is partially broken away. In this figure, bottom dump doorsare shown at 22 as pivotally suspended from pivots 23 arranged atopposite ends of the body. This enables the doors to be swung throughthe broken line positions illustrated in connection with the door at theleft side of the body, the position 22a being a partially open positionand the posiion 22b being a fully opened position in which the furtheropening movement is limited by engagement of pads 25 on the doors andstops 26 on the body. The mechanism for opening and closing one door isillustrated, it being understood that the mechanism for the other dooris identical.

A supporting bracket of U-shaped cross-section illustrated at 27 isprovided on each side of a central partition 28 which divides thepartition 20 into two compartments. Each bracket provides a pivot 29 fora bell crank lever 30 which is actuated by a hydraulic jack 31 disclosedin greater detail in FIG. 3. The jack cylinder is pivoted as at 32 inthe bracket 27 and the rod is pivotally connected at 33 to one end ofthe lever 30. The full line position of the lever 30 is the positionoccupied with the door 22 closed and the upper end of the lever contactsan adjustable stop 34. A rod 35 is pivotally connected with a bracket 36on the door and at its opposite end to the lever 30. In the closedposition shown the upper connection of the rod 35 is over center withrespect to the pivotal support of the lever so that weight of the dooror any portion of the load resting on the door will tend to close thedoor rather than to open it and will therefore not be imposed on thehydrauli cylinder and other components of the hydraulic circuit.

Hydraulic jack 31 may be partially extended to swing the door to theposition shown at 23 or may be fully extended to swing the door into theposition illustrated at 24. This is accomplished through structure shownin FIG. 3 wherein the jack is shown as having a rod 38 with a pistonhead 39 at one end thereof and a smaller or auxiliary head 40 associatedtherewith. The hydraulic circuitry and controls are not disclosed hereinas they are not considered necessary to an understanding of the pres entinvention. It will suffice to know, however, that the door jacks may beactuated from controls in either tractor cab and that they may besupplied selectively with hydraulic fluid at a nominal pressure of say1000 pounds or a higher pressure of 1600 to 2000- pounds. The jack ofFIG. 3 is illustrated in its retracted position as with the doorsclosed. To open the doors to a partially open position, fluid issupplied at the lower pressure at the head end of the jack as through apassage 42. Fluid from the rod end of the jack is discharged andreturned to the source through passage 44. When the auxiliary head 40 ofthe piston enters a reduced diameter in the cylinder 31 provided by asleeve 46 exit of fluid through passage 44 is prohibited and the pistoncomes to rest against the body of fluid within the sleeve. This is thepartially extended position which moves the door to the position shownat 23 in FIG. 2.

To impart further or full opening to the door the higher pressure isdirected to the cylinder through the port 42 and so increases thepressure within the sleeve 46 until it opens a spring-closed check valveshown at 48 permitting fluid to escape from the sleeve through theauxiliary piston 40 and out through the passage 44. Closing of the doorsis effected by directing pressure inwardly of the cylinder throughpassage 44 which will first be effective against a surface 50 in back ofthe piston 39' and later also against the face of the auxiliary piston40.

During opening of the doors, the great Weight of the load within thebody tends to open the doors more rapidly than fluid can be expelledfrom the rod end of the jack through the passage 44. In order to preventundesirable delay in the opening of the doors excessive pressure in therod end of the jack is relieved through a springclosed check valve 52communicating pressure from the rod en-d through the piston to theopposite end of the jack or in elfect bypassing fluid to permitincreased speed of the door opening operation.

What is claimed is:

Means for actuating pivoted bottom dump vehicle doors which swingoutwardly away from each other to- Ward open positions comprising alever pivoted between its ends for each door, a link pivoted between oneend of the lever and the door, an extensible jack for imparting pivotalmovement to the lever, first valve means contained within the jack bodyand responsive to a nominal fluid pressure to partially extend the jackto open the References Cited UNITED STATES PATENTS 2,401,407 6/1946Benbow 298-35 2,782,946 2/1957 Hough 91-19 X 3,076,680 2/1963 Kress298-35 3,169,491 2/1965 Darlington 105-240 3,198,579 8/1965 Adams 295-35RICHARD J. JOHNSON, Primary Examiner.

20 BENJAMIN HERSH, Examiner.

